This invention relates to a tilt lock system for an outboard motor and more particularly to an improved mechanism for operating the hydraulic system of a tilt lock system.
It is well known in marine propulsion units to include a hydraulic cylinder, piston assembly that is interposed between the outboard drive and the transom of the associated watercraft. This assembly functions to hold the outboard drive against popping up when traveling in reverse thrust but, at the same time, permitting the outboard drive to pop up when traveling forwardly and when an underwater obstacle is struck.
With this type of mechanism, it has also been proposed to provide a valve assembly which when opened permits flow through the hydraulic cylinder assembly so that the outboard drive can be manually tilted up without having to act against the resistance of the hydraulic cylinder. Such an arrangement is shown in U.S. Pat. No. 4,784,625 issued Nov. 15, 1988 and entitled "Tilt Lock Mechanism For Marine Propulsion Device." In the arrangement shown in that patent, there is a separate accumulator chamber that communicates with the two chambers of the hydraulic cylinder and check valves normally restrict the flow in one direction or the other from the hydraulic cylinder to or from the accumulator. An actuating mechanism including a rotary cam is employed for opening the check valves and permitting the unencumbered tilting up operation as described.
Although the system described in that patent is quite effective, the manual control valve that is employed to permit ease of tilting up has its operating axis disposed generally at a right angle to the axis of the hydraulic cylinder. Since this type of mechanism is normally placed between the swivel and clamping brackets of the outboard drive, this makes the valve actuator difficult to access. In addition, this type of construction adds some bulk to the overall assembly, which is not desirable.
It is, therefore, a principal object of this invention to provide an improved tilt lock mechanism for an outboard drive.
It is a further object of this invention to provide a tilt lock mechanism for an outboard drive having a release valve and operator wherein the operator will be easily accessed and the construction is nevertheless compact.
It is a further object of this invention to provide an improved release mechanism for a tilt lock cylinder of a marine outboard drive.